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A letter to the editor is presented in response to an article regarding the success of the pre-implantation genetic diagnosis for Hirschsprung disease (HSCR).

Hirschsprung disease (HSCR, aganglionic megacolon) represents the main genetic cause of functional intestinal obstruction with an incidence of 1/5000 live births. The major gene is the tyrosine kinase receptor RET. Identification of mutation in the RET coding sequence theoretically offers the possibility to perform prenatal (PND) or preimplantation genetic diagnosis (PGD). However, such procedures remain controversial. Currently available surgical therapies, although life-saving, are associated with an unsatisfactory long-term prognosis for many. In this context, at-risk couples often consider PGD as the better option to give birth to unaffected children. A couple whose male partner was affected with HSCR gave birth to two severely affected children, and was referred to our PGD centre. The mutation c.751insGC was identified in exon 4 of the RET gene at an heterozygous state in all three affected patients. We developed a specific single cell protocol in order to select unaffected embryos based on mutation analysis and an intron 4 intragenic marker segregation. PGD was performed on two blastomeres from four embryos. Three were unaffected and two of them subjected to transfer, resulting in one twin pregnancy and the birth of two heathy children. [ABSTRACT FROM AUTHOR]